Generally, breathable waterproof fabrics are used to make clothes and play a role of discharging the moisture inside the clothes and preventing the external moisture from flowing into the clothes.
In recent years, interest in health and leisure activities has been increasing, and functional breathable waterproof fabric materials have been applied to various fields, and the breathing function is emphasized more and more in a high-class and well-being boom.
Breathable waterproof fabrics are applied to outdoor wears for mountain climbing such as climbing clothes, outdoor clothes and sleeping bags, and outdoor activities and their application ranges are expanding.
Water is not penetrated into the breathable waterproof fabrics while the sweat coming from the human body is vaporized and discharged to the outside of the breathable waterproof fabrics. As a result, clothes made of the breathable waterproof fabrics are comfortable in a wearing sense.
Waterproof materials are classified into three materials such as PTFE (polytetrafluoroethylene) films, polyester films, and PU (polyurethane) lamination. Gore-Tex (which is a waterproof, breathable fabric membrane and registered trademark of W. L. Gore and Associates) includes PTFE films and is currently leading the world's breathable waterproof fabric market. However, new materials that can replace existing breathable waterproof materials continue to be developed.
Korean Patent Registration Publication No. 10-1106679 discloses a technology of manufacturing breathable waterproof fabrics in which a polyurethane nanofiber web is thermally compressed with a raw fabric on which a liquid-phase adhesive is sprayed wherein polyurethane nanofiber web comprises polyurethane nanofibers having an average diameter of 1,000 nm or less and part of the polyurethane nanofibers is a moisture-curing polyurethane nanofiber.
However, such a raw fabric can facilitate a bonding process with the raw fabric by lowering the shrinkage ratio of the polyurethane nanofiber web at room temperature. However, by spraying the liquid-phase adhesive on the raw fabric, distribution of uneven spraying of the liquid-phase adhesive in the raw fabric is obtained, and thus the breathing efficiency is not uniform and the liquid-phase adhesive is impregnated into the raw fabric, thereby interfering with the breathing such as discharging of the sweat.